<!--
 * Copyright (c) 2015 The Chromium Authors. All rights reserved.  Use of this
 * source code is governed by a BSD-style license that can be found in the
 * LICENSE file.
-->
<body>
  <iframe></iframe>
  <script>
    var frame = document.querySelector('iframe');
    var port = null;
    var seenRequest = false;

    // Message arrives from <webview>.
    window.onmessage = function(e) {
      seenRequest = true;
      port = e.source;
      if (e.data == 'load-frames') {
        // Start loading the iframe.
        frame.src = 'child_frame.html';
      }
    };

    frame.onload = function() {
      if (seenRequest) {
        var childFrame =
            frame.contentWindow.document.getElementById('child-frame');
        childFrame.onload = function() {
          port.postMessage('frames-loaded', '*');
        };
        // Load the nested iframe.
        childFrame.src = 'data:text/html,Hello';
      }
    };
  </script>
</body>
